A statistical analysis of explosive blast-loading field (test) data has revealed a high level of variability of peak reflected pressure, impulse and time of positive phase duration for repeatable tests where variability would be expected to be a minimum. The model error (accuracy) of a widely used predictive blast-load model is also assessed. A probabilistic model of blast-loading is then developed that considers variability and/or uncertainty of explosive mass, the net equivalent quantity of an explosive in terms of TNT mass, stand-off distance, air temperature, air pressure, inherent variability and model error. This type of statistical and probabilistic analysis is essential for structural reliability analysis of structures subject to explosive blastloading where load variability is an important contributor to damage and safety risks. The probabilistic blast-load model was used to calculate the probability of exceeding TMS-1300 design values of blast-load. It was found that the TMS-1300 design value for peak reflected pressure is non-conservative.